Costs Of Using “Tiny Targets” to Control Glossina fuscipes fuscipes, a Vector of Gambiense Sleeping Sickness in Arua District of Uganda

Abstract

IntroductionTo evaluate the relative effectiveness of tsetse control methods, their costs need to be analysed alongside their impact on tsetse populations. Very little has been published on the costs of methods specifically targeting human African trypanosomiasisMethodology/Principal FindingsIn northern Uganda, a 250 km2 field trial was undertaken using small (0.5 X 0.25 m) insecticide-treated targets (“tiny targets”). Detailed cost recording accompanied every phase of the work. Costs were calculated for this operation as if managed by the Ugandan vector control services: removing purely research components of the work and applying local salaries. This calculation assumed that all resources are fully used, with no spare capacity. The full cost of the operation was assessed at USD 85.4 per km2, of which USD 55.7 or 65.2% were field costs, made up of three component activities (target deployment: 34.5%, trap monitoring: 10.6% and target maintenance: 20.1%). The remaining USD 29.7 or 34.8% of the costs were for preliminary studies and administration (tsetse surveys: 6.0%, sensitisation of local populations: 18.6% and office support: 10.2%). Targets accounted for only 12.9% of the total cost, other important cost components were labour (24.1%) and transport (34.6%).DiscussionComparison with the updated cost of historical HAT vector control projects and recent estimates indicates that this work represents a major reduction in cost levels. This is attributed not just to the low unit cost of tiny targets but also to the organisation of delivery, using local labour with bicycles or motorcycles. Sensitivity analyses were undertaken, investigating key prices and assumptions. It is believed that these costs are generalizable to other HAT foci, although in more remote areas, with denser vegetation and fewer people, costs would increase, as would be the case for other tsetse control techniques.

Predicting the Impact of Intervention Strategies for Sleeping Sickness in Two High-Endemicity Health Zones of the Democratic Republic of Congo

“…Studies conducted on small islands in Lake Victoria, Kenya, targets deployed at 50–100 m intervals along the shore were estimated to impose a daily mortality of 3–6% and targets deployed at 50 m intervals along rivers in the West Nile region of Uganda, giving overall densities of ∼6 targets/km 2 in, were estimated to impose a daily mortality of 4%. Costs of deploying targets at densities of 6 targets/km 2 to impose a daily mortality of 4% were estimated at USD 84/km 2 [2, 19] which gives some indication of the potential costs associated with adding a tiny target strategy to current medical interventions.…”

“…Trials in Guinea [3], Kenya and Uganda [2] have shown that deployment of tiny targets can reduce densities of tsetse by 70% to >90%. The targets are cheap (∼US$ 1/target) and easy to deploy, hence control of the tsetse population can be achieved at US$ 84/km 2 [19]. Shaw et al .…”

Mapping the benefit-cost ratios of interventions against bovine trypanosomosis in Eastern Africa

“…These can be transported by bicycle or motorcycle, leading to much lower logistics costs than those for installing and servicing conventional targets. The costs for these were based on detailed field data collected during the tiny target operation described above (Shaw et al, 2015) which included an intensive community sensitisation exercise (Kovacic et al, 2013). The costs were adapted by increasing logistics costs by 50% to allow for deployment in more isolated areas and allowing for 10 rather than 6 targets per km 2 .…”

6. Integrated control of trypanosomosis

“…For G. fuscipes fuscipes, small targets seems more interesting than classical one, since small targets have indexes of almost 1 (Lindh et al 2009). A recent study evaluated the cost using small target against this species in Uganda and there was reduces by 48% from USD 179 to USD 85.4 per km 2 (Shaw et al 2015). For some tsetse species such as flies of the morsitans group (Diptera, Glossinidae), small targets have been proven to be inefficient .…”